A video source device is a device, such as a DVD-Video player, High-Density HD-DVD player, Blu-Ray disc player, set-top box or personal computer (PC) for example, that outputs a video signal, which may be intended for use by a display device (e.g. a television) or other downstream component. A video source device may perform various types of video processing upon source video content, e.g. to convert between formats or to improve the quality of video images. One type of video processing that a video source device may perform upon source video content is temporal interpolation. Temporal interpolation generally involves using portions of the source video content, representing at least two points in time (e.g. two video frames within a sequence), in order to interpolate (estimate) content at another point in time, e.g. in between the two. Examples of temporal interpolation video processing include certain types of frame rate conversion and de-interlacing. For clarity, the term “source video content” refers to video content (e.g. video frames or fields) that forms the basis for temporal interpolation performed by the video source device. Such source content may be received, possibly in encoded or compressed form, from a source, such as a satellite, cable television channel, terrestrial broadcast channel, DVD, hard drive, video archive or the like. Source video content is closer to the “true” images recorded by a camera than temporally interpolated video content generated therefrom. An intermediate video processor, such as a DVDO® iScan™ VP50 High Definition audio/video processor from Anchor Bay Technologies for example, is also a form of video source device.
A video sink device is a device, such as an intermediate video processor (which typically lacks display capabilities, e.g. the above-noted DVDO® iScan™ VP50 High Definition audio/video processor), or a display device (e.g. Cathode Ray Tube (CRT), Liquid Crystal Display (LCD), plasma display, Organic Light-Emitting Display (OLED), Digital Light Processing (DLP) display or Liquid Crystal on Silicon (LCOS) display for example), that receives a video signal and either processes the signal in some fashion or displays video images based on the signal. Commonly, a video sink device (e.g. a television) receives a video signal from an interconnected video source device (e.g. a DVD-Video player). The interconnection between the devices may be a cable that may conform to a known industry standard, such as VGA, composite/S-video or component out, Digital Visual Interface (DVI), High-Definition Multimedia Interface™ (HDMI™), DisplayPort®, Digital Flat Panel (DFP) Interface, Open LVDS Display Interface (OpenLDI), or Gigabit Video Interface (GVIF) standard for example. The video source and video sink devices may form part of a home entertainment system for example.
Like the video source device, the video sink device may also be capable of performing temporal interpolation video processing upon a received video signal. The temporal interpolation capabilities of the video sink device may overlap, in whole or in part, with the temporal interpolation capabilities of the upstream video source device. The reason for the overlap may be that the devices are independently marketed as modular components that are capable of interconnection with various types of complementary video source devices or video sink devices, whose temporal interpolation video processing capabilities may vary, or may be non-existent. The quality of the temporal interpolation video processing performed by the video source device may differ significantly from the quality of the temporal interpolation video processing performed by the video sink device, e.g. due to the use of different temporal interpolation algorithms or integrated circuitry by the devices.
From the perspective of a video sink device, a received video signal upon which temporal interpolation video processing has earlier been performed by an upstream video source device may be largely or wholly indistinguishable from a received video signal upon which no temporal interpolation video processing has earlier been performed. Even when it is possible to determine that temporal interpolation video processing has earlier been performed upon the received signal, the processing involved in identifying temporally interpolated video content in the video signal may be complex.
Similar issues may exist when video content is spatially interpolated.